Micromagnetic detector.



F. G. SIMPSON.

MICROMAGNETIC DETECTGR. APPLIcAloN mio APn.2a,l91a.

1,21 1,770. Patented Jan. 9,1917.

2 SHEETS-SHEET 2.

5M oemtoz M btowago FREDERICK G. sIMPsoN, or SEATTLE, WASHINGTON.

MICROMAGNETIC DETECTOR.

Specification of Letters Patent.

Patented Jan. 9, 1917.

Original application led November 1, 1912, Serial No. 729,064. Divided and this application filed April 23,

To all whom it may concern Be it known that I, Fnnnnuroir G. SIMP- soN, a citizen of the United States,l residing at Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Micromagnetie Detectors, of which the following is a specification.

This application is a divisionlof one tiled by me Nov. 1, 1912, Serial No. 729,064.

The invention herein disclosed relates to certain improvements in ancre-magnetic apparatus for the reception of signals of the Hertzian wave type.

The present invention has for its object the provision of a new and improved means for detecting the existence of voltages or currents in a wireless` telegraph receiving circuit which have been generated within such a circuit by the passage of a wave train of Hertzian wa ves.

A further object of the invention is the provision of instrumentalities which may be selectively tuned for the reception of Hertzianwave trains arriving at a certain definite rate per second, thereby preventing interference from wave trains arriving at the re .ceiving station at rates other than that adjusted for.

To this end the invention consists in the structure of parts and in the combination thereof for the purpose specified' substantially as hereinafter set forth and claimed.

In the accompanyingr drawings, which form a part of this specification, Figure 1 is a view partly in side elevation and partly in longitudinal sectionof a receiving instrument for Wireless telegraph systems. Fig. 2 represents a horizontal section of the same. Fig. 3 is Van enlarged transverse section through magnet 17, Fig. 1. Fig. 4 Is a transverse vertical section through the instrument. Fig. 5 is an enlarged' fragmentary vertical section of one of the slide members. Fig, 6 is a plan view thereof. Fig. 7 is a diagrammatic View illustrating the application of the instrument to a wireless tele raph receiving circuit.

Lemberfs 1" and 1,made' of brass or other suitable material, are coupled atone end by a base element4 2 and at the other end by a plate 42 which is supported upon Serial N0. 763,143.

base 2". The members 1 and'l" are both slotted as shown` to accommodate a magnet carriage 2G, which may be used-interchangcably with either of them. 9

23 is a core for the electro-magnet coil 2l Wound on a bobbin or spool 25, the terminals of which are carried to the binding posts 29. This core is threaded through the carriage 2G and the carriage is engaged by `a nut 27 whereby the carriage may be clamped to either of said members. A block 21, of insulating material, is supportefb by the members 1 and 1. This block supports, through the medium of the depending insulating blocks 22 and 22, a coil of tinewire 17 which is Wound about a core 1S, consisting of a number of line iron Wires, each wire being insulated4 from the others, Fig. 3. The block 21 also supports, through the medium of an arm 20, the solenoid 19 which is wound n pon the spool 20C The windings of the magnet coil 17, and the solenoid 19, are usually connected in .series with each other, the terminals, as shown in Fig. ,4 being carried to binding posts mounted on the block 21.

30 and 30 represent reeds or bands of thin steel, or other magnetizable material, of approximately twelve onehundredths of an inch in widtlr and three one-thousandths of an inch in thickness. The correspondingl end of each reed is fastened by the clips 33 to a ulley 31 of insulation. The other extremities are fastened to metallic blocks 6 fitted in the metallic bushings 7. The blocks 6 are threaded by screws 9 and' are adapted to have a short' longitudinal movement regulated by the screws. In the vicinity of its middle` the reed 30 has rigidly connected therewith a pin 16, which is constructed` of aluminum or other suitable conducting material. To reed 30 there is also connect` ed a like nin 16 in alinemelit with pin 16". On the inner-.end of pin 16 is mounted a small globule of gold, platinum or other non-oxidizing conductin material indicated at a, while on the end o pin 16' is mounted a small bloolnb of carbon. The point of contact Vbetween the elements a and 'b is capable of microphonic adjustment.

- Reed 30 passes loosely through the bobbin 20 of solenoid19. The core 18 of coil 17 is placed to permit of an air gap, ap roximately one thirty-second of an inc between its ends and the respective reeds 30 and 30". llhe pulley 31 is journaled on shaft 32 which is rigidly connected to a cylinder 34. This cylinder is fitted to move longitudinally in a stationary ring y having arms 40 Which`are rigid with members l and 1". Mounted within the cylinder is a compression spring 35, through the axis of which passes the stem of the screw 48, which also passes throughwasher 43, the end plate 42, a Washer 36, and threads into nut 37. This nut is provided with pins which extend into slots provided in the cylinder 34, thereby preventing the nut from turning. The cylinder 34 and the ring 40 are respectively provided with a key Way and key 41, which prevents the cylinder from turning in the ring. By means of screw 48, the spring 35 may be adjusted to communicate, through the medium of cylinder 34, shaft 32 and pulley 31, tension to the reeds 30 and 30". Individual adjustment of the reeds may be had through blocks 6 and screws 9.

Knife-edge pieces 14, made of ivory or other insulation, are rigidly fastened to the holders 15 which, in turn, are tted to slide upon the carriage bodies 11. The latter are each iitted at their ends to slide longitudinally upon the members 1 and l, being held in place by attachments l2. Bushings are retained by and between the carriage parts 11 and 12 and are respectively threadeel-.by the right and left screw 44, which is borne at one end b the base 2, passing through base 2 at t e other end, an being held in lace by journal-cap 49, as indicated in Fig. The holders 15 for the knife-edge pieces 14 can be made to approach to and recede from each other in pairs, bly means of the right and left screws 13. t is to be noted that two assemblages of parts herein-l after called sliders, and each made up of the parts 11, 12, 13, 14, 15 and 45, are arranged to move in longitudinal direction,

approaching to or receding from each other, by means of the screw 44; While the reeds 30 and 30 can be adjusted in a limited degree as to their distance from each other by means of the screws 13, controlling the position of the knife-edge pieces 14, which bear against them. i

Referring now to Fig. 7, 52 is a receiving antenna. 51 is a variable inductive coupling having a primary 511 and a secondary 51". The. antenna is grounded through the primary. Hertzian Wave trains arriving at the antenna induce volta es therein, which cause high fre uency oscil atingl currents to How through t e anten'na and t e primary to and from the earth. These currents, by inductive action through the inductive coupling 51, produce voltages within the secondary circuit, consisting of the secondary coil 51',

the condenser 53, the solenoid coil 19 and the electro-magnet coil 17.

Reed 30 lies Within the magnetic field of the electromagnet coil 24, wound about core 23. This magnet is excited by current from the battery 56. The voltage at the terminal of coil 24 is ca able of adjustment through the medium o the regulatin rheostat 55. The density of the magnetic eld in the vicinity of 30 can be regulated by variation of the exciting current, and also by movement of the core 23. 'Oscillating currents of high frequency flow through coils 19 and 17, producing motion in reeds 30 and 30". In the absence of these oscillating currents, the reed 30 is moved slightly away from its position of normal rest by the magnetic attraction of the core 23 of the electro-magnet 24, and a state of'magnetic polarity exists in said reed at a point opposite the core. Magnetism is also communicated to a lesser degree to core 18 of coil 17. Upon the arrival of a series of Hertzian waves, high frequency oscillating currents flow through coils 19 and 17, which in effect partially suppress the magnetic condition of the reed 30 and the core 1S, respectively, permitting the reed because of mechanical tension thereon to recede slightly from the ma et core 23. At the same instant the high requency currents flowing through coil 17 lnduce within the core 18 an oscillating magnetic flux, which has an integrating tendency to attract reeds 30 and 30 to its extremities. The phenomena described are simultaneous in their action jand have a tendency to draw reeds 30 and 30 closer together, thereby decreasing resistance at the microphonic contacts a and b, which permits an increased How of current from the generator 57 through the reed 30', pin 16', carbon element Z), gold element a, pin 16, reed 30 and galvanometer 60, or other suitable indicatlng or signaling instrument. i

As each series of Hertzien waves communicates but a single impulse to the reeds 30 and 30, each reed Wil1,if properly proportioned, vibrate at the frequency of the wave trains, i. ei, at the same rate per second of vibrations as is the rate per second in the number of wave trains arriving at the receiving station. This phenomenon is due, as

natural period of vibration shall be the same y as the frequency `of the incoming Hertzien wave trains. Assuming new, that it be deaired td receive signalsy a transmitting 13 station sending forth wave trains at aY rate ot lool) per second, while wave trams of the same wave length are being sent forth by another transmitting station at a rate ot' l2() per seeond. without interference; the micromagnetic detector being previously adjusted to respond to a frequency ot 120 impulses per second. This result can be accomplished by either increasingl the tension on 18 reeds 30 and 30 by means of the screw 39,

or by drawing the sliders closer together by means of the screw -l-l. or by means of both. The active lengths of the reeds. lying between the sliders. can be so adjusted as to respond to a frequency of impulses ot 100() per second eren though there may be iinpulses at other rates per second at the same time communicated to them.

It cai, he readily seen` therefore. that the 20 micro-magnetic detector described herein.

may be so constructed as to be capable of adjustment for vibration of itsI reeds by varying the active length thereof, or the tension thereon. so that they will respond l'iyyibrating to impulses comnumi|-ated to them as hereinaboe described by llertzian wave trains arriving at a preselected frequency. and that Hertzian ware trains arriving at any other frequency than that adjusted for.

will not produce such riln'ations, and thereshould not be confounded with the adjustment for electrical resonance by properly portioning the capaeity and induetance in the receiving circuit or circuits, which adjustment is entirely electrical and is made .for the frequency of the oscillations within the wave trains themselves. or in other words, for the wa ve length oi" the llcrtzian wares. The adjustn'ient in the micro-magnetic detector is made to the frequency ot 45,the ware trains. and is entirely mechanical in its nature.

The invention claimed is:-

1. In a wireless telegraph system, the combination with two suitalily supported magnetizable reeds disposed at a suitable di.-

tance from and parallel with each other, ot means for Changing the natural and fundamental rate of vibration of each of said reeds, means for magnetically polarizing to a,

desired constant degree one of said reeds.

an electro-magnet disposed to extend lengthwise between said reeds. and adapted to be energized to attract. said reeds each toward the other, a heli): et insulated wire disposed to surround one of said reeds whereby electrical energy may be caused to change the magnetic condition of said reed, and a pair ot movable electrical contact points associated with and adapted to be controlled by said reeds.

ln a receiving apparatus of a wireless telegraph system, the combination with two magnetizablc members suitably supported to adapt themv to vibrate, ot' independent means for magnetizing one of said members to a desired normal degree, electro-magnetic means adapted to change the said normal degree of magnetizatioii, an electro-magnet disposed to adapt it to operato to change the distance between the movable portions of said members, two electrical contact points associated with the movable portions ot said members and adapted to be actuated therebv to varj7 the electrical resistance of their contact. and means for adjusting each ot said members to have a desired natural and fundamental rate o' vibration.

3. In a receiving apparatus ot' a wireless telegraph system, the combination with a suitable supporting frame, oi a shaft mounted to rotate in bearings within said frame. equal portions ot said shaft being provided one with a left-handed and the other with a.

right-handed screw thread. carriers adaptedto be moved in guide ways disposed within said frame. one ot' said carriers heilig provided with a left-hamled screw thread which is disposed to engage with the lefthanded screw thread ot' said shaft while the other ot' said carriers is provided with a right-handed screw thread and disposed to engage the right-handed screw thread of said slrat't. whereby said carriers are adapted to approach toward and recede from each other in responsaV to a rotation in a proper direction ot `said sha tt. two reeds of magnetizalile material each of which is stretched between adjustable supports that are adapted to vary their tension, Isaid reeds being disposed parallel with each other and parallel with the path traveled by said carriers, projecting arms fixed in each ol said carriers and disposed to engage with and press against said reeds whereby, when said carriers are moved toward each other and away trom each other, the active length of said reedsI may be changed, and adjustable morable electro-magnetie means for changing the magnetic conditioiis ot' said reeds.

4. ln a micro-magnetic receiving instrument, the combination of adjacent ribrating reeds, engaging microphonie contacts carried by said reeds, means for varying the y,length of the yibratory portions ot' said reeds, means for magnetizing one of said reeds, an electro-magnet located between the reeds for attracting them, and an adjustable electro-magnet whose field includes the magnetized reed and the core of said first electro-magnet.

In a micro-magnetic receiving instrument, the combination of a vibratory reed,

magnetizmg helix surrounding it, mlierophonic contacts actuated by said reed, an

l electro-magnet for attracting said reed in one direction, and a second electro-magnet for attracting said reed in the opposite direction, the coil of the second magnet being in series circuit with said helix and havin its core in the field of the first magnet an composed of fine individually insulated iron wires. D

(i. In a micro-niagnetic receiving instrument, the combination of a supporting frame, vibratory reeds stretched therein, engaging microphonic contacts carried by said reeds, devices for individually adjusting said reeds, a device for simultaneously adjusting the tension of said reeds, carriers movably mounted in said frame and having arms for engaging said reeds, adjusting means for varying the distance between said carriers, adjusting means for varying the distance between said arms upon each carrier, and electro-magnetic means for actuating said vibratory reeds. j

7. In a micro-magnetic receiving instrument, the combination of a supporting frame, vibratory reeds stretched therein, engaging microphonic contacts carried by said reeds, devices for individually adjusting said reeds, a device for simultaneously adjusting the tension of said reeds, carriers movably mounted in said frame and having arms for engaging said reeds,` adjusting .means for varying the distance between said carriers, adjusting means for varying the distance between said arms upon each carrier, electro-magnetic means for attracting said vibratory reeds toward eachother, and an electro-magnet mounted in said frame for adjustment lengthwise of said reeds and having a core adjustable toward and from one of said reeds. i A

8. In a receiving apparatus for wireless telegraph systems, a magnetizable element i capable of directly responding to particular Hertzian Wave trains by means of magnetic fields produced adjacent to, and one of which surrounds a portion of, said element when said Wave trains exist in a wireless receiv-` ing circuit.

9. In a receiving apparatus ior wirelessI telegraph systems, a ma etizable and vibratable element dispose Within a helix, and means to produce a magnetic field adjacent to said element, the helix and the means cooperating with said element to cause the element to immediately and resonantly respond to the frequencies of a Hertzi when the frequency of the wave train in a` wireless receiving circuit is the same as the :frequencyV of the element, through the medium of separate and distinct magnetic fields produced adjacent thereto, one of said fields surrounding a portion of said member.

1l. In a-receiving apparatus for wireless telegraph systems, a flexible and magnetizable member capable of directly responding by maximum vibration to Hertzien Wave trains having a like definite frequency of vibration on their assage through a wireless receiving circult, including electromagL netic `means adapted to produce magnetic fields adjacent to said member, one of said lgieans surrounding a portion of said mem- 12. In a receiving apparatus for Wireless telegraph systems, a magetizable element Y capable of directly/responding by maximum vibration to Hertzian wave trains having a corresponding frequency when the trains are -of which surrounds a portion of, said element, said Vfields being produced by the actionjof directly impressed electromagnetic wave`-traiiisarriving at definite speed to produce the maximum vibration of the element when adjusted tomespond to the wave train frequen'cy, A .f Si e1 at Seattle, Wash.,th1s 15th day of Apr 1913.

i FREDERICK G.' SIMPSON.y

Witnesses:

PIERRE BARNES, E. Pn'rniisoiv. i

Gopicl of this patent may be obtained for tiva cents auch, by addressing the Commissioner of Patenti,

` Washington?. 0. r 

